Magnetic Resonance Imaging and Computed Tomography Findings in Arrhythmogenic Right Ventricular Cardiomyopathy

Right ventricular cardiomyopathies: a multidisciplinary approach to diagnosis

The physiological importance of the right ventricle (RV) has been underestimated over the past years. Finally in the early 1950s through the 1970s, cardiac surgeons recognized the importance of RV function. Since then, the importance of RV function has been recognized in many acquired cardiac heart disease. RV can be mainly or together with left ventricle (LV) affected by inherited or acquired cardiomyopathy. In fact, RV morphological and functional remodeling occurs more common during cardiomyopathies than in ischemic cardiomyopathies and more closely parallels LV dysfunction. Moreover, there are some cardiomyopathy subtypes showing a predominant or exclusive involvement of the RV, and they are probably less known by cardiologists. The clinical approach to right ventricular cardiomyopathies is often challenging. Imaging is the first step to raise the suspicion and to guide the diagnostic process. In the differential diagnosis, cardiologists should consider athlete's heart, congenital heart diseases, multisystemic disorders, and inherited arrhythmias. However, a multiparametric and multidisciplinary approach, involving cardiologists, experts in imaging, geneticists, and pathologists with a specific expertise in these heart muscle disorders is required.

Cardiovascular health, part 1: preparticipation cardiovascular screening

CONTEXT

Identification of potentially fatal cardiac conditions in otherwise healthy athletes presents a major challenge to the sports medicine community. The requirements for preparticipation screening vary among countries and even from state to state within the United States. The mandated use of an electrocardiogram as a screening implement has provoked international controversy.

EVIDENCE ACQUISITION

Part 1 of this review highlights the current guidelines and controversies surrounding cardiovascular screening, with a focus on the diagnostic challenges associated with identifying athletes with inheritable cardiomyopathies. Data sources were limited to peer-reviewed publications from 1984 to the present.

RESULTS

Preparticipation screening should include at least a history and a physical examination for all athletes, whereas use of an electrocardiogram is still controversial. Diagnosis of inherited cardiomyopathies presents unique challenges, particularly in hypertrophic cardiomyopathy, where many features can mimic those found in the "athlete's heart."

CONCLUSIONS

Recognizing cardiac conditions in athletes that can predispose them to sudden cardiac death or other adverse outcomes is of vital importance, as is the appropriate exclusion of these athletes from competition. Further studies are needed to determine the most efficient and cost-effective means of screening and to increase the sensitivity and specificity of diagnostic testing for inheritable cardiovascular diseases.

Late gadolinium enhancement of the right ventricular myocardium: is it really different from the left ?

It has been suggested that, in late gadolinium enhancement, the signal of right ventricular myocardium is nulled at a shorter inversion time than the left. While we initially made the same observation, we believe that the difference is not real, but results from artifacts. We present 7 cases as well as computer simulations to describe the nature of these artifacts and explain how they can create the impression of different inversion times for the right and left ventricle. At inversion times that are shorter than ideal for the myocardium a black rim can be seen at the border of the myocardium with blood on the inside and with fat on the outside. This is most likely a partial volume effect. The thin myocardium of the right ventricle is sandwiched between these black rims and, at a low spatial resolution, is no longer visible. In this case, the adjacent black rims may then be misinterpreted as myocardium. While black rims also occur on the left side, the myocardium is thicker and remains discernable as a separate layer. As a consequence, the optimal inversion time for the right ventricle only appears different from that for the left. In fact, in the presence of hypertrophy of the right ventricle or during systolic wall thickening we did not find a difference in inversion times between the left and right ventricle. We conclude that sufficient spatial resolution is important for adequate late gadolinium enhancement of the right ventricle.